I heard a recent LCD-3 and it sounded like my 2 but a bit lusher, did;t detect any resolution difference minus some treble refinement. Hifiman had a winner with the HE-500 but they bought out the HE-560 which doesn't improve anything and moves away form what made it loved. The HE-400 is a fun headphone yet the HE-400i and HE-400 go too far away from the HE-400's bass and fun.
The Nighthawks are what the headphone hobby needed yet audiophiles cry that it has too much bass.. it doesn't, it just has bass and audiophiles hate bass so they downvoted it. The fun is sucked out of all these new headphones. Pricing has gone through the roof more than ever before, 3k headphones are now the thing..none of them out perform the best at 1-2k.
I quite like the Hifiman X but £1300?! what are Hifiman smoking, I'd take the HE-500 over them anyday - X sound slower than the HD650 which is £230!